Manipulator for working in non-accessible spaces



May 5, 1970 H. WALISCHMILLER v MANIPULATOR FOR WORKING IN NON-ACCESSIBLE "SPACES Filed Aug. 9, 1967 2 Sheets-Sheet l Inventor 5%! f May 5, 1970 3,510,011

MANIPULATOR FOR WORKING IN NON-ACCESSIBLE SPACES Filed Aug. 9, 1967 H/WALISCHMILLER 2 Sheets-Sheet United States P nt Q Int. Cl. B25j 3/00 US. Cl. 214-1 6 Claims ABSTRACT OF THE DISCLOSURE A manipulator for working in non-accessible spaces, in particular for working with radio-active substances, which comprises a control arm and a receiving arm. Rotary shafts connect operatively the control arm with the receiving arm. A protecting wall includes a lead-in and a lead-in tube is rotatably mounted in the lead-in of the protecting wall. The rotary shafts are disposed in the lead-in tube and means include the rotary shafts leading to the control arm and disposed in the lead-in tube. A protecting box receives and surrounds the receiving arm. The protecting box and the receiving arm form a single unit, and means for sealing off the single unit against the escape of gas and dust.

The present invention relates to a manipulator for working in non-accessible spaces, in general, and in such manipulator for working with radioactive substances in non-accessible spaces, in particular, in which the working movements are transmitted from a master or control arm to a slave or receiving arm by means of rotary shafts disposed in a shielding wall lead-in, and in which the receiving arm is surrounded by a shielding box (for instance, a so-called alpha-box) inserted into a screened cell, which shielding box contains dangerous gasand dust-like substances.

.By the shielding box the remaining cell space should be kept free from the mentioned substances, so that there, under circumstances, a working by the application of carrieror protecting gases is still possible. Difiiculties are encountered, however, if the receiving arm is to be removed for an exchange or for purpose of repair. For this purpose, in the known structures, the shielding box is, at first, removed from the receiving arm by means of a lifting jack and the receiving arm is then separated from a protecting wall lead-in. In order to prevent thereby, that the dangerous gasand dust-like substances, which are disposed in the shielding box, contaminate the receiving arm or can enter the control side through the wall lead-in, the receiving arm has been equipped previously with a gas-tight, bag-like shielding envelope of suitable synthetic material, which, on the one hand, is secured at the upper connecting flange of the receiving arm, and, on the other hand, within the range of the gripping tool in a gas and dust-proof manner.

Such envelope does not olfer, however, with suificient safety the desired protection, since the material of the envelope becomes brittle, porous and thereby leaks during passage of time under the influence of the radiation, whereby then a particular danger of damage upon occurrence of strong mechanical and thermal strains as well as of gas pressures is present.

In order to remove these possible dangers and drawbacks, respectively, and in addition to obtain improvements concerning the mounting and dismounting of the receiving arm, it is one object of the present invention to provide a manipulator for working in non-accessible spaces, wherein the shielding box jointly with the re ceiving arm is applied as a removable unit to the parts leading to the control arm, whereby this unit is sealed off against an escape of gas and dust. By this arrangement, it is brought about that the receiving arm remains in the shielding box also after the separation of the parts leading to the control arm side and can be removed jointly with the latter, for instance, by means of a sluice from the cell. In this case, even after removal of the shielding box, an escape of contaminated gas and dust into the cell and, thereby, through the shielding wall opening is prevented by seals built into the removed parts. As additional safety, the parts of the wall lead-in opening to the cell space can also be sealed off.

It is another object of the present invention, to provide a manipulator for working in non-accessible spaces, wherein two types of embodiments are provided, which are determined by the prevailing structural situations, for instance, the length of the lead-in openings in the wall and the thickness of the shielding wall, respectively, and the depth of the shielding box.

It is another object of the present invention to provide a manipulator for Work in non-accessible spaces, wherein in case of shielding walls which are made of a material with high shielding effect, for instance metal, and thus can be held weaker, an embodiment is provided in which the shielding box is secured to a protecting tube containing a lead-in tube, which protecting tube is terminated on the control arm side, on which also the seals and the connecting means for the transmission parts are arranged.

Here, also, during removal of the shielding box with the receiving arm, the connecting parts reaching up to the control arm side are Withdrawn from the shielding Wall, whereby these parts remain on the shielding box and are removed with the latter from the cell. In long shielding wall lead-ins, the parts remaining on the shielding box render more difficult, however, the manipuation. In order to avoid this drawback, in accordance with the present invention, the unit consisting of the shielding box and the receiving arm is remova'bly connected on the receiver arm side by means of a connecting member with the lead-in tube, whereby the connecting member is equipped with a rotary bearing sealed against gasand dust-passage, for the lead-in tube, as well with the connecting members of the rotary shafts and their sealed bearings. In accordance with the present invention, a very effective sealing is brought about such, that between the immovable part connected with the box and the rotary part of the connecting member connected with the lead-in tube, an annular space is provided which is oil-tight in the outward direction, which annular space is continuously filled with oil and is in communication by means of channels with the sealed oil spaces of the shaft bearings in the connecting member.

Since, in manipulators of the described type, the working movements are transmitted from the control arm to the receiver arm by rotary shafts which are disposed in the lead-in tube, the separation and connection of the shaft parts mounted in the connecting member and in the leadin tube are possible by use of plug couplings in a simple manner. It is thereby of advantage that the necessary axial displacements of the connecting member with the receiving arm and the shielding box can be performed from the control arm side, which is achieved in accordance with the present invention such, that on the connecting member, a holding nut is concentrically secured to the connecting piece, in the inner thread of which holding nut the end of a holding rod supported axially on the lead-in tube is threadedly connected which can be rotated from the control side. This arrangement can be applied also, in an advantageous manner, upon use of the connecting member to the lead-in tube.

In order to make possible the connection of the receiving arm with the connecting member quickly and safely and also to release the same, in accordance with the present invention, a bolt connected with the holder for the receiving arm and concentrically lead-in is axially displaceably mounted, which bolt has inner thread, in which a threaded bolt supported on a holding nut is axially threadedly connected. In a structurally simple manner is thereby made possible the operation of the threaded bolt, in accordance with the present invention, such, that the head of the threaded bolt is disposed in a recess of the holding nut and is accessible after removal of the connecting member through the threaded bore of the holding nut to the operating tool.

By these means, the holder with the receiving arm can be axially displaced and be separated from the connecting member or connected therewith. The receiving arm held thereby by a lifting jack is in suitable manner for instance, by two lateral carrying pins, is able to be suspended from above into a hook-like bearing of the holder. The axial displacement used basically during the connection and separation of the receiving arm makes possible, thereby, simultaneously the loosening and connecting, respectively, of the sections of the transmitting shafts equipped with plug connections.

While, as above described, in an arrangement of a separating point on the receiving side of the shielding wall, the position of the lead-in tube and its protecting tube is set in the wall and thus also the fillings disposed between the protecting tube and the wall opening can be maintained in a prefabricated stage in storage and in this connection, certain difliculties exist by arrangement of the separating point on the control arm side. These difficul-. ties result from the fact, that here the distance of the protecting tube connected with the box from the wall opening and its lining, respectively, is determined by the prevailing position of the. box in the cell, so that the dimensions of the fillings can vary strongly, which is in so far of a disadvantage, as the filling member from case to case must be produced separately.

In order to remove also this drawback, in accordance with the present invention, the space between the lining tube of the shielding wall lead-in and the protecting tube is filled in with tensioned metal rods. These rods, which may be comparatively thin, are inserted after a completely mounted arrangement in the free shielding wall space and pressed in, respectively, until the space is filled and the rods are retained by pressure locking through a radial tension.

With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:

FIG. 1 is an elevation of a manipulation for working in nonaccessible spaces designed for short wall lead-ins;

FIG. 2 is a similar elevation designed for long wall lead-ins; and

FIG. 3 is an axial sectionof a part disclosed in FIG.2, shown at an enlarged scale.

Referring now tov the drawings, the manipulator designed in accordance with the present invention comprises a control arm 1, a receiving arm 2, a protecting tube 4, the latter passing through a lead-in opening in a shielding wall 3, and a shielding box 5.

In the embodiment disclosed in FIG. 1, the protecting tube 4, which contains a lead-in tube 6 with the transmission parts, is secured to the shielding box 5, The protecting tube 4 terminates on the other, so-called cold side of the shielding wall 3 at T. In this range are disposed also the plug couplings 7 for the transmission shaft 8, so that upon separation of a connecting plate 9, the control arm 1 can be removed and the shielding box 5 With the receiving arm 2, the tubes 4 and 6 as well as the transmission parts contained therein can be moved in the direction of the arrow P out of the shielding wall into the cell Z. In order to prevent thereby a passage of contaminated gasand dust-particles through the bearing members disposed in the tubes, an intermediate wall 11 is disposed in the tube 6 in which the bearing members for the transmission shafts 8 sealed by sealing rings 12 and oil. chambers 13 are disposed. Between the tube 4 and the tube 6 rotatably mounted therein, a further sealing 14 is provided, which is formed of elastic U-shaped rings and likewise surrounds an oil chamber, which communicates with the other oil chamber 13. A further sealing 15 can be arranged on the hot side between the tubes 4 and 6. The mentioned sealing points prevent also the escape of contaminated particles out of the shielding box, if the latter jointly with the tubes 4 and 6 are separated from the control arm. The passage opening in the protecting wall can then remain open and an entering of the cell Z is possible without danger. The space 16 between the protecting tube 4 and the shielding wall opening is filled up in conventional manner by suitable rings, which serve as additional holding means for the protecting tube 4. Since, however, the position of the protecting tube is determined by the level position of the shielding box, the distance between the protecting tube 4 and the shielding wall opening 10 can vary from case to case, In order to save thereby the expense for the production of exactly 15 filling rings, around rods 17 are driven into the space 16 which are retained by its clamping effect and which can be removed again prior to the removal of the tube 4.

Referring now again to the drawings, and in particular to FIG. 2, the embodiment disclosed in FIG. 2 is preferred for such arrangements, in which the protecting tube 4' has an appreciable length due to a strong shielding wall 3', so that the manipulation during removal of the protecting box would be rendered very difiicult. In order to avoid this drawback, the separation is performed at the point T whereby then a particular connecting member 20 is provided, which is secured to the shielding box 5 and.which contains the rotary bearings sealed off dustand gas-escape.

It is particularly clearly shown in FIG. 3, the connecting member 20 has a bearing ring 21 on which a plate 22 is mounted. The latter is disposed on the protecting tube 4 and on the other hand is connected with a bearing body 23, which contains the bearings 24 of the shaft members 25 with the seals 26, as well as the seal 27 for the rotary bearing 28. In known manner, the sealings 26 and 27 consist of elastic U-shaped rings which define annular chambers 29 and 30, which are filled with oil which are filled with oil which can be supplied from a container 31. Behind the flange ring 32 surrounding the connecting member 20 is provided a round cord sealing which seals off the engaging slot in outward direction.

The intermediate members 25 mounted in the connecting member 20 for the transmission shafts, of which for instance the shaft 35 is shown, are connected with the latter by means of plug couplings 36 by locking off the forces, whereby in known manner the part 37 is secured against rotation in the uncovered position by means of a locking claw 38 and is free for rotation in its coupling position. By this arrangement, it is avoided that in case of a separation of the connecting shaft 25 from the transmission shafts 35, the transmission means can perform non-controllable movements in the receiver arm. The transmission shafts 35 are led through to an intermediate plate 40, so that also in the separate condition of the shafts, the position of which is retained in the bores of the plate 40, which provides a certain advantage for the mounting and for the assembly and the connection of the shaft parts, respectively.

In order to connect and to separate, respectively, the connecting member 20 to and from, respectively, the protecting tube 4, a holding nut 41 is concentrically secured on the plate 22, in the inner thread 42 of the holding nut of which the end 43 of a holding rod 44 can be threadedly connected, which can be rotated from the control side and which supports itself thereby on the lead-in tube (not shown). By rotation of the rod 44 in one direction, the connecting member 20 is displaced in axial direction from the tube 4, while a rotation in the other direction causes a pushing of the connecting member up to an engagement in the plane T whereby also the shaft couplings 36 and 37 are released and engaged, respectively.

On the other side of the connecting member 20, arrangements are provided, which permit in an advantageous manner to separate and to connect, respectively, the receiving arm from and to, respectively, the connecting member 20. For this purpose, a holder 48 is provided for the connecting head 47 of the receiving arm 2, in which holder 48 is screwed a holding bolt 49. The latter is axially displaceable in the bearing body 23 and has an inner thread 50, into which a threaded bolt 51 can be threadedly inserted, the head 52 of which engages on the one hand the holding nut 41 and on the other hand the connecting member 20 and which is equipped with an inner hexagon 53. In case the holding rod 44 is removed, thus during the separated connecting member 20, this inner hexagon is accessible through the threaded bore 42 for the operating tool, so that upon rotation of the bolt 51 in one direction, the holding bolt 49 with the holder 48 is axially moved away from the bearing body 23 and upon rotation in the other direction, is pulled to the bearing body 23. Since the shaft members 25 mounted in the body 23 are connected also in the connecting head 47 by plug couplings 54 with the shaft sections 55 leading to the receiving arm 2, during removal and connection, respectively, of this arm an automatic releasing and connection, respectively, of the transmission shafts takes place, whereby the described locking devices 37 and 38 are likewise used.

The connecting head 47 is equipped with two radial carrying bolts 56, which make possible, in an advantageous manner, to set down and to lift from this hearing upwardly, respectively, the receiving arm suspended during the assembly and disassembly to a lifting jack into or out of a fitting bearing 57. By this arrangement, the exchange of the receiving arm and the removal thereof from the shielding box 5 is appreciably simplified.

As can be ascertained from FIG. 3, an escape of damaging substances from the shielding box 5 can be prevented with safety, even upon removal of the receiving arm 2', since also the rotatable bolt 51 is sealed at the passing point and the holding nut 41 is outwardly sealed off by means of the sealings 58 and 59.

While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claims.

I claim:

1. A manipulator for working in non-accessible spaces, in particular for working with radio-active substances, compnsrng a control arm,

a receiving arm,

rotary shafts operatively connecting said control arm with said receiving arm,

a shielding wall having a lead-in opening,

a lead-in tube rotatably mounted in said lead-in opening of said shielding wall,

said rotary shafts disposed in said lead-in tube,

means including said rotary shafts leading to said con trol arm and disposed in said lead-in tube,

a shielding box receiving and enclosing said receiving arm,

said shielding box and said receiving arm jointly forming a single unit, and

means for sealing off said single unit against the escape of gas and dust.

2. The manipulator, as set forth in claim 1, wherein said lead-in tube comprises a protection tube secured to said shielding box and terminating on the side of said control arm,

said rotary shafts constituting transmission means between said control arm and said receiving arm,

said sealing means for sealing off said single unit disposed in said protection tube,

a connecting piece releasably connecting said protection tube with said single unit on the side of said receiver side, and

said connecting piece includes a rotary bearing sealed against gasand dust-escape for said protection tube, intermediate members and bearings having sealed oil chambers.

3. The manipulator, as set forth in claim 2, which includes an immovable part connected with said shielding box,

said connecting piece includes a rotatable part connected with said protection tube,

said immovable part and said rotatable part define an annular chamber oil-tight in outward direction,

channel members leading to said sealed oil chambers of said bearings, and

said annular chamber is adapted to be filled with oil and communicating with said oil chambers of said bearings.

4. The manipulator, as set forth in claim 3, which includes a holding n ut having inner thread and concentrically secured to said connecting piece,

a holding rod axially supported on said protection tube,

and

one end of said holding rod threadedly connected to said inner thread of said holding nut and the other end of said holding rod rotatable from the control arm side.

5. The manipulator, as set forth in claim 4, which includes a holder means connected with said receiving arm,

a bolt connected with said holder means and axially displaceable and concentrically disposed in said connecting piece,

said bolt has an inner thead, and

a threaded bolt having a head axially supported on said holding nut and threadedly connected with said bolt.

6. The manipulator, as set forth in claim 5, wherein said holding nut has a recess,

the head of said threaded bolt is disposed in the recess of said holding nut, and adapted to be accessible to an operating tool through said inner thread of said holding nut upon removal of said connecting piece.

References Cited UNITED STATES PATENTS 3/1966 Bowyer 214-1 1/1967 Walischmiller 2141 X 

